Apparatus for feeding fine fuel.



J. A. WELTON. APPARATUS FOR FEEDING FINE FUEL.

APPLICATION FILED MAY 29, 1913.

127 1 36. Patented Feb. 2, 1915. I

2 SHEETS-SHEET 1 J. A. WELTON.

APPARATUS FOR FEEDING FINE FUEL.

APPLICATION FILED MAY 29.1913.

Patented Feb. 2, 1915. v

2 SHEETS-SHEET 24 JOHN A. WELTON, F CANAL DOVER, OHIO.

APPARATUS FOR FEEDING FINE FUEL.

memes.

Specification of'Letters Patent.

Patented Feb. 2, 1915.,

Application filed May 29, 1913. Serial No. 770,718.

To all whom it may concern:

Be it known that 1, JOHN A. \VELTON, .a citizen of the United States, residing at Canal Dover, in the county of Tuscarawas wand State of Ohio, have invented certain new and useful Improvements in Apparatus or Feeding Fine Fuel, of which the folowing is a specification.

This invention relates to certain new and useful improvements in apparatus for feeding fine-fuel to furnaces and burning the same therein.

The apparatus comprises means for the initial reduction of the fuel;means for further reducing the fuel into fine and coarse particles; means for feeding the coarse particles into the combustion chamber of a furnace where it will serve as apilot fire; means for separating the fine particles from the coarse particles and feeding said fine particles into the combustion chamber of the furnace where they may be burned in suspension or over the pilot fire of coarse fuel; means for regulating the feed of the material automatically by boiler conditions; and means for supplying an adequate sup ply of oxygen to facilitate combustion of the fuel in the combustion chamber.

My invention further consists of the parts and the constructions, arrangements and combination of parts which I will hereiniifter describeand claim.

In the accompanying drawings forming part of this specification and in which simil.r reference characters indicate like parts in the several views ;Figure 1 is a longitudinal sectional view of part of a boiler furnace and associated grinding mechanism embodying the salient features of mv inven- 40 tion. Fig. 2 is a cross section of the fire box on the line 2-2 of Fig. l, omitting the pressure regulating devic2s. Fig. 3 is a vmodification showing the grates upon which the pilot fire may be burned. Fig. 4 is a detail of the mechanism for regulating the action of the feed screw, 9. Fig. 5 is a cross sectional view through a grinding device of modified form..

In carrying out my invention I may use the leading features thereof in connection .with any well known and desired form of furnace. In the drawings I haveillustrated my invention in connection with a locomoti e boiler-furnace of any approved construct on and which furnace has a combustion chamber, 1, to which access is afforded through a fire-door, 2. The combustion chamber is operatively connected to a boiler, 3, and in the combustion chamber is arranged a curved fire-arch, 4, of refractory material and which arch may include a series of curved bars, or tubes, 5, one or both ends of'which may be suitably connected to a union or other coupling, 6. The arch, 4, is composed of fire-brick or the like and in or through said arch is formed a series of openings or perforations, 7, through which a part of the products of combustion may escape to the space in rear of the arch, said arch terminating'at its upper end short of the front wall of the combustion chamber so as to form a flue or passage for the greater portion of the products of combustion.

It will be understood that the fire-box may have any desired form and its shell may be of any design and construction well known in the art, and that the furnace shown is but illustrative of any furnace with'which the leading features of my invention may be operatively connected.

The aforesaid arch rises from the bottom of the rear end of the combustion chamber and extends in a curve forwardly of the direction of the front of said chamber, so as to overhangthe grate, or suitable twyers,

the top of the arch being spaced from the top of the fire-box, so that the products of combustion may pass over the same to the rear end of the fire-box, and through the same to the ordinary flues with which the boiler of the type of furnace shown will in practice be supplied. The arch extends throughout the entire width of the fire-box and is constructed of fire-brick or other re fractory material, and it may have a construction similar tothat which appears inmy former Patent Number 993,928, dated May 30, 1911, without departing from the spirit of the present invention.

The lower portion of the firebox casing is provided with a curved trough, 8, in which operates a screw conveyer, 9, adapted to feed fuel into the bottom of the combustion chamber for the purpose of serving as a pilot-lire, as I will hereinafter describe.

The walls of the combustion chamber may also be lined with fire-brick, 10. or other refractory material as shown in F'g. 2, and in the lower pot on of the combustion chamber'at each side of the center. thereof, is a twycr, 11, which consists of a pipe stitute; for,

perforated in its upper portion and adapted to discharge air into or upon the bed of fuel in the combustion chamber, each of said twyers having one end opening through the bottom of the fire-box casing, as shown in Fig. 1, whereby anyashes filtering into the twyer through the perforations may be readily discharged; this discharge end of the twyer is provided with some suitable form of damper or valve, 12, by means of which .the passage through the twyer may be tion of the furnace fire-box is an apparatus and under such roll from the feeding means above.

for reducing the fuel to such condition that it may be delivered into the combustion chamber of the furnace in such quantities conditions as will promote complete combustion of the fuel and at the same time insure maximum heating properties. T 0 this end, 1 construct a suitable casing, 14, with a hopper, 15, or like receiver for the coal or material to be crushed or ground, and to which hopper the coal may be conveyed or delivered in any manner and by any of the mechanisms commonly used in this art for the purpose, and in order to obtain the desired feed of this material to i the crushing devices,I use some appropriate form of feed regulator, the character of which isunimportant, although I. have shown in the present. drawings for illustrative purposes a regulator in the form of a tubular damper, 16, which is supported above a horizontal rotatable disk, 17, having a raised or conical center for directing the material toward the edge of the disk and underthe lower edge of the tubular damper, said disk being provided with a toothed surface, 13, adapted to be engaged by a beveled pinion, 19, mounted on a shaft, 20, journaled in the casing and operated by any well known means. The shaft carrying the pinion, 19, may have its outer end provided with a sprocketwheel, 21, while the opposite end carries aspur gear, 22, adapted to mesh with a similar gear,-23, on the shaft of the agitating roll, 24:, which roll may be of any suitable character and if desired, provided with teeth or spikes, to more effectually act upon the material delivered to the Below the roll, 24, which I prefer to term theagitating roll, since the purpose of said roll is to agitate the material passing from the feeding devices, is a crushing roll, 25, of any well known character suitable for my purpose, to which the coal is fed and by which it is crushed and fed forwardly to be further reduced by devices which I will presently describe. The crushing roll operates in the bottom of a crushing chamber and the bottom of this chamber is formed of a plate, 26, of sufficient strength to resist the crushing action of the roll, said plate being preferably yieldingly supported upon suitable springs, 27, and said plate having openings, 28, through it for the passage of material reduced by the roll and of sufficient size to readily pass through the perforations into a trough, 29, which is alined with and fo ns a part of a trough, 8, formed below the rebox of the furnace and in which the screw conveyer, 9, operates, wherebythe material passing through the perforated bottom of the crushing chamber and thereby separated from the balance of the material may be fed by the screw into the combustion chamher-and onto or between the twyers or grates therein. This separated material may represent what I term the coarser particles of the fuel used by me and it is designed to serve as a pilot-fire upon and above which the liner material hereinafter mentioned will be burned.

The crushing roll, 25, may be operatedby a sprocket chain, 32, running from the sprocket wheel, 21, to a pinion, 33, on the shaft of the crushing roll. The crushing roll may have spiral ribs or may have its periphery otherwise formed to insure thefeeding of material longitudinally of the roll and to suitable pulverizing or reducing devices'which I will now describe.

The casing, 34, in which the feed regulating means and the crushing devices before described, are mounted, is extended one side and this casing is provided withfsuitablebearings for the opposite ends'or' the shaft, 35, which carries the crushing roll. The shaft, 35, is the main shaft of the apparatus and power is applied toit through the medium of a motor, 35', or other connection which may be of any desired well known type; On the shaft, 35, adjacent the crushing roll, is arranged a muller-wheel,

36, which is designed to act uponmaterial fed by the roll into the chamber in which the muller-wheel operates and in which chamber this material is further reduced. The chamber has its wall provided with an opening, 37, through which some of the material reduced in the chamber by the mailerwheel will be permitted to escape into the trough in which the screw conveyer, 9, operates whereby this material may be fed by thescrew into the combustion chamber with such other material as may have entered the screw from the initial crushing chamber. as

' before described. On theshaft, 35, I also edly secure a plurality of muller-wheels, 38, each of which is substantially of truncated form and each of which, as well as the mullerwheel, 36, has an open center or is otherwise constructed to form a passage lengthwise of the shaft through which the fine material produced in the crushing chamber, either by the action of the crushing roll, or by the agitation of the roll, 24, will be drawn from the crushing chamber through said passage and willbe delivered pneumatically into the combustion chamber of the furnace. To this end the casing, in which the mullers operate is provided with a fan-chamber, 39, in which a rotary fan, 40, of some appropriate form operates, to induce a draft from the initial crushing chamber through the open mullers so that the line material picked up by the draft will be delivered from the easing into the pipe, 11, and finally discharged into the combustion chamber of the furnace through the medium of a discharge head, 42, with which the pipe communicates, said discharge head being of any suitable character and having as many branches as may be desired and one form of which is shown in my prior Patent No. 993.928, before mentioned.

Appropriately mounted in the horizontal extension of the casing,,3l, and surrounding each of the truncated formed mullers. is a ring or annulus, 43, which may be substantially triangular in cross section, whereby its inner face substantially conforms to the in- I clinationor taper of the periphery of the coacting truncated formed inuller-wheels.

In Fig. 1, I show the two muller-wheels, 38, as being relatively reversed and accordingly the ring or annulus, 43, which sur rounds these muller-wheels, will be likewise relatively reversed. The purpose of this construction is, that one of the muller-whcels will balance the other when under working conditions, since by reversing one mullerwheel relatively -to the other, or reversing the angular position of the outer surface of the pair of muller-wheels, I am permitted to balance the pressure due to centrifugal force in the chamber in which the pairof muller-wheels operate. I thus overcome the end thrust which would otherwise occur.

during the operation of the machine and I maintain the relation between the grinding surfaces of the mullers and their co-acting rings or annulus so as to obtain the greatest grinding capacity with a minimum of resistance and horse power.

In addition to the fan and fan-casing heretofore described and which are em ployed for delivering the fine-fuel under pressure into the combustion chamber below the curved arch. I place alongside of the firstmentioned fan. a second fan, 44, which operates in a suitable case or chamber, into which leads an inlet pipe, 45, whichis valveinto the casing during the operation of the second fan may be regulated, said casing having discharge openings,--l6, which communicate with the front ends of the twyers, 11, positioned in the lower part of the combustion chamber, it being understood that the casing, in which the second-named fan operates'has two outlets, one of which coinniunicates with each of the aforesaid perforated twyers, whereby air delivered from the second-nan1ed fan, will be discharged into the twyers under pressure, it being assumed that the outer ends-of thesetwyers are closed, and air will be delivered through the perforations upon or through the bed of coarse fuel which may constitute a pilot-fire for the furnace.

Provision is made for the automatic operation of the foregoing devices, whereby the furnace fire is controlled according to the pressure in the boiler, the fuel supply being reduced when the boiler pressure rises above a predetermined point and being increased when the boiler pressure drops belocated in the upper portion of the furnace,

said tube being open to the atmosphere at the outer end, and said rod, 45, extending through this open end and being connected to one arm of the bell-crank lever, e7, pivotally mounted on the front of the furnace shell, the other arm of said lever being provided with a series of holes, to any one of which may be pivotally connected the upper end of a rod, l8, whose lower end is likewise adjustably pivotally connected to an arm, 49, of a lever, 50, which is pivoted at one end to a suitable bracket 51 and has its opposite portion slidable over a quadrant, 51. To this lever is also pivotally connected the upper end of a rod, 52, which is designed to extend to a crank-arm. 53, on a horizontal shaft, 54, and which shaft is provided with an eccentric, 55, from the strap of which extends a rod, 56. The arrangement and operation of the foregoing parts are similar to what is shown and described in my prior Patent No. 993,929, dated May 30, 1911. and which specific features form no essential part of the present claimed invention.

()n the shaft of the feed screw, 9, is fixedly secured a disk or wheel, 60, having ratchet teeth and on the said shaft is also pivotally connected a pitman, 61, Fig. 4-, to the outer end of which is connected it the agitating roll, Ell, whereby the agitating of a pivoted finger,

roll and feed-screw are operated in unison. The pitman, 61, is provided with a pivotal dog or pawl, 65, and to this dog is connected an arm, 66, which is provided with a curved slot, 67, through which passes a bolt, 68, whereby the arm may be adjusted to regulate the throw of the pawl or dog. On the shaft of the feed screw is also mounted a lever, 69, the lower end of which is pivotally connected by a link, 70, to theshort arm 71, 72, as shown in Fig. l, adapted to contact withan arm on the pawl for the purpose of disengaging the pawl during the operation of the hand lever, said lever having intermediate of its ends, an arm, 73, to which is connected the upper end of the adjustable rod, 56, which is fixed to the strap of a suitable eccentric, 55, mounted on the shaft, 54, the said lever having its upper portion providedwith an extension or handle, 76, pivotally mountedthereon, which may, operate over a curved segment or like part whereby the lever may be rocked and adjusted and held in any of its adjusted positions, to thereby fix the throw of the pawl or dog, 65, and the consequent rotation of The operation of these the feed screw.

parts is substantially as follows: The movement of the crank, 53, is trans-- mitted to and actuates the lever, 69, which in turn actuates the finger, 72, the purpose of which is to keep the pawl, 65, from contacting with the ratchet on the wheel, 60, when the boiler pressure is high. As the lever, 61, is operated through the rod, 63, and crankarm, 6st, it carries with it the pawl, 65, and the slotted lever, 66, the levers, 61 and 66, and pawl, 65, being free to move up and down a distance equal to the throw of the crank-, 64r. As the lever, 61, is loosely mounted relatively to the lever, 69, and as both are freely mounted on the shaft, 31, of the feed screw, it is quite evident that the movement of lever, 61, cannot in any way interfere with the operation of the lever, 69, and vice versa. The lever or handle, ed on the upper portion of the lever, 69, and has a short arm, 76*, adapted to bear down slightly on the end of the slotted arm, 66, to thereby disengage the pawl, 65, from the ratchet teeth onthe wheel, 60, and stop the operation of the feed screw, but without changing the air and fine coal supply. It is understood that the lever, 76, operates over the curved segment, 6", before mentioned, which is rigid with the lever, 69, so that as the cam, or eccentric, 55, moves the lever,- 69, the segment and the lever, or extension, 76, are carried with the aforesaid lever, 69. In other, words, the lever, 69, with its arm, 73, and segment, 7 6", and the lever, 76, are so connected that they will move in unison manner-that it may be trolled t6 admit such quantities of air as- 76, is pivotally mountthe crushing chamber about the shaft, 31, and during the rocking movement of the lever, 69, the finger, 72, is likewise moved to actuate the pawl, 65, in the manner before described.

In Fig. 5 1 show a modified fdrm of mechanism for feeding fuel to the grinding devices and wherein I employ suitable gates or plates which enter the casing from op posite sides and whose inner edges are adapted to approach and recede from each other to regulate the feed of the material from the receiving chamber, a, into the crushing chamber, 5, said gates controlling the communication between these two chambers, and each of the gates being slidably mounted and being actuated by a screw shaft, 0, having quick threads operating in a nut, d, said screw shaft being connecte to a lever, e, to which is connected a link, f, which in turn is connected to an arm or link, 9, on the shaft, 54', this construction being substantially disclosed in my former application filed December 2, 1912, Serial Numher 7 39,593, and is illustrative of a different type of feeding mechanism from that before disclosed.

he casin of the a varatus ma also be air into the grinding chamber between the agitating roll and thecrushing roll, it being understood that the shutter or damper controlling said opening may be connected to the other parts of the apparatus in such automatically conwill best promote the combustion of the fuel, and it being apparent that the finer fuel delivered through the crushing and muller chambers will be delivered into the furnace through the burner head by the action off the suction fan, and that the air inlet open; ing referred to provides for the proper draft through the apparatus for the purpose speci' fied. I have also'shown in'the upper portion of the steam dome of the boiler a pressure regulator, 80, which may be of any well known character and from which a pipe, 52, may lead to any well known form 0 steam-turbine, as forinstancein the manner substantially as shown in my former Patent Number 993,929, dated May 30, I 1911. Around the upper portion of the muller casing Iimay also provide a space, 81, forming a passageway for coarse particles of coal to escape from the initial muller chamber and thence toithe feed screw, 9, where it may be conveyed by the latter into the furnace to be burned on the grate, or twyers, any suitable feeding devices being used in this space for the purpose mentioned, as may be desired.

Frcm the foregoing description it will be understood that coarse cral may be-fcd into in a state of agitation and will be crushed in this chamber, the

particles in the form of dust being drawn through the apparatus and delivered through the pressure-head into the combuscoarse particles of fuel from the finer particles, aconveyer connecting with the firelox of the furnace adapted to feed said coarse material into the presenceof said bed 'supporting elements to form a pilot fire,

tion chamber below the arch thereof; and.

that other portions of the fuel will be progressively ground while passing the mullers to be eventually reduced to substantially dust-like form and delivered through the burner-head as before described. I am thus permitted to provide a mechanism whereby coarse hard particles will be delivered to a feed screw or the like to be fed to a pilot fire on the grates or in the space between the twyers, while the finer fuel will be delivered into the combustion chamber above the pilot fire there to be burned in suspension. I do not have to reduce all of the coal to powderlike form and this results in a saving in the power required to operate the apparatus. The advantage in my construction over a regularly under-fed fire is that where the dust is fed in over the pilot fire, all the heat generated from the dust is produced without the accumulation of cinder and clinker; another advantage is that the air passing through the coal on the grates, or twyers, is heated and toned down before it impinges on the brickwork or lining of the fire-box. The feed screw feeds the pilot fire but a comparatively small amount of coal, and as the greater portion of the heat is produced by the fine particles burned in suspension, it is evident that the clinker trouble of the ordinary furnace is practically elimi-v nated. I

It will be understood that the foregoing features may be used in connection with such accessories and minor features of detail as would be commonly employed for the transmission and control of power from one part to another, without departing from the spirit of my invention. It will also be understood from the foregoing that when an engine is in a station or passing through a city or populous community, the feed screw, 31, can be stopped and the dust fire alone employed, which will practically eliminate the smoke emitted from the engine. In other words, the feed screw may be employed only at such times that the engine is called upon to do the maximum amount of work, when it may be necessary to start the screw and feed some of the coarser fuel to assist the dust fire.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. In apparatus for feeding and burning fine fuel, the combination with a furnace having a combustion chamber and elements upon which a bed of fuel may be supported, of a crushing mechanism for initially reducing the fuel, means for separating the and pneumatic means connecting with the crushing chamber and combustion chamber of the furnace adapted to conduct the fine material pilot fire.

2. In apparatus for feeding and burning fine fuel, the combination with a furnace having a combustion chamber and elements in the bottom thereof upon which a pilot fire may be burned, of'a casing connecting with the furnace, fuel-feeding means within said. casing, crushing elements within the casing adapted to reduce said material, said casing having means for separating the coarse particles of fuel from the finer particles, grinding elements succeeding the crushing elements adapted to further reduce the fine particles, means for inducing a draft through the casing and grinding ele ments, whereby the draft acts as a vehicle for carrying the fine material, said casing having a discharge conduit connecting with the furnace and adapted to deliver the fine material into the combustion chamber thereof, and a conveyer for delivering the separated coarse material into the combustion chamber to form a bed of pilotfire above which the, fine material is burned in sus-.

pension.

3. In apparatus for feeding and burning fine fuel, the combination with a furnace having a combustion chamber and elements ticles. grinding elements succeeding the crushing elements adapted to further reduce the fine particles, means for' inducing a draft through the casing and grinding elements, whereby the draft acts as a vehicle for carrying the fine material. said casing having a discharge conduit connecting with the furnace and adapted to deliver the fine material into the combustion cham er thereof, a convever for delivering the separated coarse material into the combustion chamher to form a bed of pilot fire above which the fine material is burned in suspension, and means for supplying air under pressure into the presence of said pilot fire.

4. In apparatus for feeding and burning fine fuel, the combination with a furnace having a combustion cham er and elements in the bottom thereof upon whicha pilot fire may be burned, of a casing connecting.

into said combustion chamber where it is burned in suspension above said i. if)

with the furnace, fuel feeding means within said casing. crushing elements within the casing adapted to reduce saidmaterial, said casing having means for separating the coarse particles of fuel from the finer particles, grinding elements succeeding the crushing elements adapted to further reduce the fine particles, means forinducing a draft through the casing and grinding elements, whereby the draft actsas a vehicle for carrying the fine material, said casing having a discharge conduit connecting with the furnace and adapted to deliver the fine material into the combustion chamber thereof. a conveyor for delivering the separated coarse material into the combustion chamber to form a bed of pilot'fire above which the fine material is burned in suspension, and means connecting with the conveyer for regulating the movement of the same and the feed of the coarse material to the pilot fire.

5. In apparatus for feeding and burning fine fuel, the combination with a furnace having a crmbustion chamber and elements in the presence of which a pilot fire may be sustained, of a casing, fuel feeding means therein, means for agitating the fuel in the casing, grinding elements within the casing adapted to reduce said material, means for separating by gravity, the coarser from the finer particles of the material, a pneumatic conveyer connecting with the interior of the casing adapted to serve as a carrier for the fine material, said pneumatic conveyer adapted to deliver the fine material into the combustion chamber of the furnace, a conveyer for delivering the separated coarse particles of fuel into the combustion chamber to supply a pilot fire therein, and means for operating the second-named conveyer to regulate the feed of the coarse material.

6. In apparatus for feeding and burning fine fuel, the combination with "a furnace having a ccmbustion chamber and elements in the presence of which a pilot fire may be sustained, of a casing, fuel feeding means therein, means for agitating the fuel in the casing, grinding elements within the casing adapted to reduce saidfmaterial, means for separating by gravity the coarser from the finerparticles of the material, a pneumatic conveyer connecting with the interior'of the casing adapted to serve asiacarr" r-for the fine material, said "pneumatic' -conveyer.

adapted to deliver the fine material into the combustion chamber of the furnace, a

conveyer for delivering the separated coarse particles of fuel into the ccmbustion chamher to supply a pilct fire thereiinand means for regulating the feed of the coarse material.

7. In apparatus for feeding'and burning fine fuel, the con'ibination with a furnace having a combustion chamber and elements in the present of which a pilct fire may be sustained, of a casing, fuel feeding means therein, n'ieans for agitating the fuel in the casing, grinding elements within the casing adapted to reduce said material, means for V separatii'ig by gravity the coarser from the finer particles of the material, a pneumatic conveyer c nnecting with the interior of the casing adapted to serve as a carrier for the fine material, said pneumatic conveye-r adapted to deliver the fine material into the combustion chamber of the furnace, a conveyer for delivering the separated coarse particlesof fuel into the combustionchamher to supply a pilot fire therein, means for operating the second-named conveyer to regulate the feed of the coarse material, and an air blower adapted to deliver air under pressure into the presence of the pilot fire.

8. In fuel feeding and burning apparatus. the combination with a furnace having a combustion chamber, of a casing, fuel feeding means in said casing, crushing elements in the casing adapted to reduce the material, said casing having means fcrseparating by gravity the coarse from the fine particles of reduced material, a conveycr for delivering said coarse particles into the fire box to form a bed constituting a pilot fire, a pneumatic conveyor serving as a carrier for the fine material and adapted to deliver said material into the combustion chamber of the furnace Where it is burned in suspension above the pilot. fire, means succeeding the crushing devices for further reducing the matel'ialfrom which the finer particles have been removed, said pneumatic conveyer adapted to separate and deliver into the combustion chamber the fine particles asthe grinding prcgresses, and an air blower connecting with the fire-box adapted to blow air under pressure thereinto in the presence of the pilot fire.

In testimony whereof I affix my signature inpresence of two witnesses.

JOHN A. 'WELTON -Witnesses:

S. L. HOLMES, A. V. LIND. 

